Espoo, Finland
Espoo, Finland
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Wuethrich C.,METAS | Alisic S.,Institute of Metrology of Bosnia and Herzegovina | Bergoglio M.,INRIM - Istituto Nazionale di Ricerca Metrologica | Saxholm S.,MIKES | And 3 more authors.
Metrologia | Year: 2016

Many laboratories within Euramet started a calibration service in medium and high vacuum recently and did not have the opportunity to take part to a comparison before. In order to assess the uncertainty budget and the quality of the measurement of these laboratories, an intercomparison, Euramet 1040 registered as Euramet.M.P-S7, from 0.1 mPa to 0.9 Pa has been organised. The participants are the CMI (Czech Republic), EIM (Greece), IMT (Slovenia), INRIM (Italy), IMBIH (Bosnia Herzegovinia) and MIKES (Finland) while METAS (Switzerland) is pilot laboratory. Three laboratories (INRIM, CMI and METAS) involved in this work have a primary definition of the pressure. Two spinning rotor gauges and a control electronic are used as transfer standard. The circulation of the transfer standard is organised as a succession of loops with a measurement by the pilot between each participant. A reference value has been determined based on a weighted mean of the results of the primary laboratories. All the participants have demonstrated their equivalence in the definition of the pressure. This comparison has been used as pilot comparison for the CCM.P-K14 project which covers the same scope with similar transfer standards.

Pokatilov A.,Metrosert Ltd. | Satrapinski A.,MIKES | Kubarsepp T.,Metrosert Ltd. | Martens O.,Tallinn University of Technology
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2010

Four high-accuracy LCR meters have been compared with the use of Metrosert and MIKES impedance standards. Specifications of LCR meters have been verified at frequency of 1 kHz for the resistance range from 1 Ω to 100 kΩ, for the capacitances in the range from 100 pF to 1 μF and for 100 mH inductor. The performance of LCR meters have been compared also at frequencies from 1 kHz to 1 MHz with ac resistors of different types, at 1 kHz and 100 kHz with 100 pF - 1 μF capacitance standards, and at 1 kHz with 300 μH - 300 mH inductance standards. Results of measurements presented in this summary confirm the specified uncertainty of the tested LCR meters. © 2010 IEEE.

Semenov Yu.,VNIIM | Satrapinski A.,MIKES
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2010

Series resonance (SR) method was investigated for the realization of 100 mH inductance at 1 kHz in VNIIM and MIKES. Practical details of the application of this method and comparison with the results of realization by the Maxwell-Wien Bridge method are presented. Results showed that 1 σ uncertainty of the 100 mH realization by SR method at 1 kHz can be at the level of parts in 10 6. © 2010 IEEE.

Kalmbach C.-C.,Physikalisch - Technische Bundesanstalt | Schurr J.,Physikalisch - Technische Bundesanstalt | Ahlers F.J.,Physikalisch - Technische Bundesanstalt | Muller A.,Physikalisch - Technische Bundesanstalt | And 3 more authors.
Applied Physics Letters | Year: 2014

Precision measurements of the quantum Hall resistance with alternating current (ac) in the kHz range were performed on epitaxial graphene in order to assess its suitability as a quantum standard of impedance. The quantum Hall plateaus measured with alternating current were found to be flat within one part in 107. This is much better than for plain GaAs quantum Hall devices and shows that the magnetic-flux-dependent capacitive ac losses of the graphene device are less critical. The observed frequency dependence of about -8 × 10-8/kHz is comparable in absolute value to the positive frequency dependence of plain GaAs devices, but the negative sign is attributed to stray capacitances which we believe can be minimized by a careful design of the graphene device. Further improvements thus may lead to a simpler and more user-friendly quantum standard for both resistance and impedance. © 2014 AIP Publishing LLC.

Palafox L.,Physikalisch - Technische Bundesanstalt | Behr R.,Physikalisch - Technische Bundesanstalt | Nissila J.,MIKES | Schurr J.,Physikalisch - Technische Bundesanstalt
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2012

Josephson impedance bridges have been reported to provide uncertainties close to that from the best conventional bridges when comparing two 10-kΩ resistors. The accuracy of a few parts in 10 8 has been extended to the comparison of two 100-pF capacitance standards, significantly improving the uncertainty for these measurements at power line frequencies. Preliminary measurements of Josephson quadrature bridges are also presented with uncertainties at the level of 1.6 × 10 -6 (k = 1). © 2012 IEEE.

Novikov S.,Aalto University | Satrapinski A.,MIKES | Lebedeva N.,Aalto University | Iisakka I.,MIKES
IEEE Transactions on Instrumentation and Measurement | Year: 2013

Epitaxial 4H-SiC graphene films for use in ambient gas sensing are fabricated and tested. The sensitivity response to nitrogen dioxide is optimized by varying both operation temperatures and humidity. A relative resistance change response of-45% is obtained upon application of elevated temperatures and a gas mixture containing NO2 at a concentration of 10 parts per billion (10 ppb). The sensitivity response increased linearly with NO 2 concentration, reaching-60% at a concentration of 250 ppb, followed by saturation at 1 part per million (ppm) level. © 2013 IEEE.

Novikov S.,Aalto University | Lebedeva N.,Aalto University | Satrapinski A.,MIKES
Journal of Sensors | Year: 2015

We report about technology of fabrication and optimization of a gas sensor based on epitaxial graphene. Optimized graphene/metal contact configuration exhibited low contact resistance. Complementary annealing of graphene sensor after each gas exposure led to significant improvement in the sensing performance. The response of the annealed sensor to the nitrogen dioxide (NO2) was tenfold higher than that of an as-fabricated graphene sensor. NO2 concentration as low as 0.2 parts per billion (ppb) was easily detectable. Devices have high signal-to-noise ratio. The detection limit of the graphene sensor was estimated to be 0.6 ppt (parts per trillion). The present technology with additional annealing improves the performance of the graphene based sensor and makes it suitable for the environmental nitrogen dioxide gas monitoring. © 2015 S. Novikov et al.

Novikov S.,Aalto University | Lebedeva N.,Aalto University | Satrapinski A.,MIKES
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2014

Quantum Hall effect (QHE) devices based on epitaxial graphene films grown on SiC were fabricated and studied for development of QHE resistance standard. The graphene-metal contacting area in the Hall devices has been improved and made using double metallization process. The tested devices has initial carrier concentration of 3 1011 cm-2 and showed half-integer quantum Hall effect at relatively low (4 T) magnetic field. © 2014 IEEE.

Merev A.,TUBITAK - Marmara Research Center | Hallstrom J.,MIKES
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2014

The high-voltage DC measuring system based on bandgap voltage references has been used for high accuracy with low dynamic resistance up to 20 kV. The measuring system is stable output over a wide range of operating current and ambient temperature, and it is insensitive to effects due to leakage currents. One of the most important parameters of a reference system is its long-term stability. This paper describes the long-term performance of a high-voltage DC reference measuring system based on bandgap voltage references. © 2014 IEEE.

Suomalainen E.-P.,MIKES | Hallstrom J.,MIKES
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2014

High voltage capacitance bridge can be calibrated at fixed ratios using traceable standard capacitors. Typical ratios to be calibrated are 10 to 1 and 100 to 1. Substitution method can be used to reduce bridge related errors and uncertainties. When a capacitor under calibration deviates significantly from the reference capacitor, substitution method is not any more applicable and linearity of a capacitance bridge has to be considered. This paper describes a method to investigate linearity of a high voltage capacitance bridge. The method is based on two reference capacitors and two simultaneously sampling voltmeters. Results of the linearity test of four largest decades of a current comparator capacitance bridge are presented. © 2014 IEEE.

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